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I purchased this machine in October 2015 at an online auction site. It's my first electric calculator.

This calculator has been manufactured by Brunsviga in Braunschweig (Brunswick), Germany. Its factory was originally dedicated to sewing machines, and obtained the rights to manufacture calculating machines using Odhner's design in 1892. Brunsviga, however, continued improving the design: according to John Wolfe, Franz Trinks, Brunsviga's engineer, registered more than 40 patents in the U.S. between 1905 and 1925, and received a honorary doctorate from Braunschweig University.

The Brunsviga 11e was manufactured between 1952 and 1955. Based on its serial number, my machine was probably made in 1953 ou 1954. The machine is a little smaller than the FACIT C1-13, but with lower capacity: 7-digit input, 6 digits in the counter and the accumulator has 11 digits, as opposed to the FACIT C1-13's 13 digits.

The 10-04 model was the very last manual calculator manufactured by Facit in Sweden. The model is very similar to the CM2-16, with the same specs, and a few external differences, including a plastic cover. It has a handle that pops out in the lower front to help moving the machine around in an office desk.

This one is in pretty good shape, but the lubrication inside is the most deteriorated I have seen. Much grease has been applied, and it hardened in some parts. When I got it, it was completely stuck. Some directed cleaning and a thorough spray of kerosene have loosened part of the main subsystems, but it was not nearly enough. A full disassembly and cleaning was required, so that the machine could operate smoothly again.

I finally got around to disassembling, cleaning and reassembling the machine in January 2014. Inside, most parts are yellowish, I guess from zinc plating. This plating has reduced the number of stains in the sheet metal parts, but most of the problem was, again, the old lubricants. I experimented this time with a small and cheap ultrasonic cleaning device, using kerosene as a solvent (see photo below). It worked very well, especially with gears, screws and other parts with holes and details that are hard to get at with a brush or a cleaning cloth.